1. Technical Field
The present invention relates in general to improvements in manufacturing technology and in particular to improvements in manufacturing technology in computer based manufacturing process plans. Still more particularly, the present invention relates to a method and apparatus for the selective suspension and resumption of computer based manufacturing processes.
2. Description of the Related Art
Manufacturing technology has long had as its primary goal the ability to consistently produce a high quality product. Over the years, the efforts which have been made to achieve this goal have been directed primarily to the improvement of the documentation which is utilized by the manufacturing technician or floor operator during the manufacturing process. However, the rapidity with which the manufacturing process evolves often renders hard copy documentation obsolete soon after it has been distributed. The probability that the primary documentation utilized by the floor operator is either downlevel or incomplete will often result in degradation in either product quality or consistency.
As a result of the aforementioned problem, it has been a recent goal in manufacturing circles to implement the so-called "Paperless Factory." The foremost object of a Paperless Factory system is to provide high quality information on the manufacturing plant floor. High quality information in this sense is information which is current, understandable, complete and consistent. Product data currency is a key issue in those areas where manufacturing is presented with frequent Engineering Change (EC) activities. The level of detail and clarity of the information provided to the manufacturing plant floor is important and its value is clearly reflected in the quality of the physical product which is being manufactured.
There are several additional motivations for the implementation of a Paperless Factory. The most obvious motivation is the ability to provide highly current data and configuration management to the shop floor. The information being utilized by the manufacturing technician on the manufacturing shop floor in performing the manufacturing or repair operation should be the most advanced Engineering Change (EC) level available.
A well implemented Paperless Factory will also eliminate or reduce the process specifications and documentation presented in paper format to the shop floor and replace those specifications with on line operator guidance which meets the shop floor requirement of high quality current information. Another advantage of the Paperless Factory implementation is the elimination of the shear volume of hard copy information required for the manufacturing process. It is not uncommon in certain manufacturing processes to require several hundred pieces of paper for building a particular product, such as a jet aircraft.
One problem which exists in the implementation of a Paperless Factory is the inability of known computer based systems to permit the operator to temporarily suspend a selected manufacturing process. For example, a manufacturing technician may take a break, go to lunch or reach the end of his or her shift during a long cycle time operation. It is necessary, in order to preserve the quality of the product under production, for the manufacturing technician to be able to conserve the status of the process under execution. Similarly, a parts shortage or defective component may require a manufacturing technician to stop work on a particular order. While waiting for a resolution to this problem, the operator needs to remain productive by working on other orders which may be completed without delay.
In view of the above, it should be apparent that a need exists for a method and apparatus within a computer based manufacturing process system which permits the selective suspension and resumption of manufacturing processes.